brotherdarrell
12-04-2012, 10:23 PM
:veryconfu I am very confused and could use some ideas. Yesterday I cast a little over 600 Lee 452-200-RF from a six cavity mold that has probably dropped close to 8K boolits over the years. When dropped from 50/50 ww/pure the boolits have always dropped around .4515", with a little bit of frost. They are also water dropped. This go round I was using some mystery alloy that air cools a little over 7bhn and water drops around 12bhn.
55334
I have cast several different molds with this alloy with few difficulties. This casting session resulted with diameters all over the board from .440" to .450" when miced opposite the parting line. The crazy thing is most of the diameters across the parting line are very close to .451". I am also getting a little shinier frost. Weights on the small diameters are about 2-3 grns. less. Fill out seams to be good, but if the mold gets a little too hot it almost appears as if parts of the boolit slumps when released from the mold; imagine a mud slide. There were also a couple of boolits where the nose fractured when the mold was opened even though I was running the pot cooler than normal and was not casting fast. Sprues were setting up in about 3 - 4 seconds, I would wait about a 2 counts then cut. Boolit bases were solid.
Good diameter
55335
small diameter
55336
good
55337
small
55338
Sorry for the poor pics, it's the best my poor camera can do. Other than turning down the pot a little my casting routine was no different than any other time. I now have over 600 boolits that need to be re-melted. I would like to not have a repeat occurrence if possible.
Any help would be greatly appreciated.
brotherdarrell
55334
I have cast several different molds with this alloy with few difficulties. This casting session resulted with diameters all over the board from .440" to .450" when miced opposite the parting line. The crazy thing is most of the diameters across the parting line are very close to .451". I am also getting a little shinier frost. Weights on the small diameters are about 2-3 grns. less. Fill out seams to be good, but if the mold gets a little too hot it almost appears as if parts of the boolit slumps when released from the mold; imagine a mud slide. There were also a couple of boolits where the nose fractured when the mold was opened even though I was running the pot cooler than normal and was not casting fast. Sprues were setting up in about 3 - 4 seconds, I would wait about a 2 counts then cut. Boolit bases were solid.
Good diameter
55335
small diameter
55336
good
55337
small
55338
Sorry for the poor pics, it's the best my poor camera can do. Other than turning down the pot a little my casting routine was no different than any other time. I now have over 600 boolits that need to be re-melted. I would like to not have a repeat occurrence if possible.
Any help would be greatly appreciated.
brotherdarrell